Manuel A. Leiva-Guzmán

• Ph.D.
• Professor (Associate) at University of Chile Facultad de Ciencias

This study provides a comprehensive overview scoping review and bibliometric of air pollution research in Chile from 1980 to 2022. The analysis reveals a significant increase in scientific production, a 9.2 annual growth rate, and an H-index of 60. The research spans 33 countries and is influenced by environmental sciences, meteorology, and atmosph...

This study is a comprehensive analysis of the oxidative potential (OP) of particulate matter (PM) and its environmental and health impacts. The researchers conducted a bibliometric analysis and scoping review, screening 569 articles and selecting 368 for further analysis. The study found that OP is an emerging field of study, with a notable increas...

An evaluation of the air quality in the mega-industrial area of Quintero-Puchuncaví is presented through the analysis of the concentration levels of PM10, PM2.5, SO2, CO, O3 and NO2 registered at 10 sites of the official air quality monitoring network in the area between 2010 and 2021. Particulate fractions and sulfur dioxide have been identified a...

Most fine ambient particulate matter (PM2.5)-based epidemiological models use globalized concentration-response (CR) functions assuming that the toxicity of PM2.5 is solely mass-dependent without considering its chemical composition. Although oxidative potential (OP) has emerged as an alternate metric of PM2.5 toxicity, the association between PM2....

Background There is evidence that global anthropogenic climate change may be impacting floral phenology and the temporal and spatial characteristics of aero‐allergenic pollen. Given the extent of current and future climate uncertainty, there is a need to strengthen predictive pollen forecasts. Methods The study aims to use CatBoost (CB) and deep l...

Continuous measurements of PM10, PM2.5, and PM1 concentrations were carried out by collocating a GRIMM Aerosol Laser Spectrometer model 11-C as a reference instrument and three Plantower PMS7003 low-cost sensor (LCS) from June 11, 2019, to April 23, 2020, in a residential/commercial area of the city of Santiago de Chile. Completeness, precision, li...

Among the air pollutants, particulate matter (PM) is one of the most important environmental risk factors for human health (Dominski et al., 2021; Fuller et al., 2022). Short-term positive associations between mortality and exposure to PM are well documented. The chemical composition of PM, such as heavy metals, has been shown to influence the heal...

The present comprehensive study provides a detailed bibliometric analysis of the oxidative potential (OP) of particulate matter (PM). This area of research is rapidly expanding and has significant implications for human health and the environment. We carefully screened 569 articles. 368 studies were selected for further bibliometric analysis. Our b...

The oxidative potential (OP) has gained attention as a parameter that can reveal the ability of different properties of particulate matter (PM) to generate reactive oxygen species (ROS) into one single value. Moreover, the OP is also believed to be a predictor of toxicity and hence health effects of PM. This study evaluated the OP of PM10, PM2.5, a...

AtmChile is an R package that permits the download and management of data from the National Air Quality Information System (SINCA, Spanish acronyms) and the Chilean Meteorological Directorate (DMC, Spanish acronyms) for multiple air quality and climatological parameters in a simple and intuitive platform. The AtmChile package includes the ChileAirQ...

This study delves into the photochemical atmospheric changes reported globally during the pandemic by analyzing the change in emissions from mobile sources and the contribution of local meteorology to ozone (O3) and particle formation in Bogotá (Colombia), Santiago (Chile), and Sao Paulo (Brazil). The impact of mobility reductions (50%–80%) produce...

We investigated the influence of local meteorological conditions and number of visitors on ambient particulate matter (PM) mass concentrations and particle fraction ratios at the Plitvice Lakes National Park between July and October 2018. Outdoor mass concentrations of particles with aerodynamic diameters of less than 1, 2.5, and 10 μm (PM 1 , PM 2...

An air pollution assessment in a small city located in the heart of Chilean Patagonia is presented. Seven years (2014‐–2020) of PM concentration levels retrieved from two monitoring stations permits an evaluation of the city's pollution variability, the effect of meteorological variables and long-term trends of air pollution. The highest PM concent...

This study aimed to estimate the environmental cancer disease burden in adults attributable to fine particulate matter (PM2.5) exposure using Ostro's function methodology, and health risk indexes for particle-bound toxic chemicals through hazard quotients (HQ, HI) and carcinogenic risk (CR, CRI) indexes from EPA guidelines, of two urban Chilean Mun...

A monitoring campaign of the atmospheric particulate matter (PM) size distribution (between 0.25 and 10 μm in diameter (Dp)) in an urban area with high levels of air pollution between June 2018 and May, 2019 is presented. The relative contribution of 24 size fractions to the total number and mass concentration of PM was analyzed using an aerosol sp...

We present the effects of the confinement and physical distancing policies applied during the COVID-19 pandemic on the concentrations of PM10, PM2.5, NO, NO2 and O3 in 16 cities in central and southern Chile. The period between March and May in 2020 was compared with the corresponding months during 2017-2019, using surface data and satellite inform...

The implementation of confinement and physical distancing measures to restrict people’s activities and transit in the midst of the COVID-19 pandemic allowed us to study how these measures affect the air quality in urban areas with high pollution rates, such as Santiago, Chile. A comparative study between the concentrations of PM10, PM2.5, NOx (NO2...

The sanitary measures implemented to control and prevent an increase in infections due to the COVID-19 pandemic have produced an improvement in the air quality of many urban areas around the world. We assessed air quality during the COVID-19 pandemic for particulate matter (PM2.5 and PM10), NO2 and O3 in in metropolitan area of Lima, Peru between p...

An evaluation of the concentrations of PM10, PM2.5, SO2, CO, NO2, O3 and meteorological variables recorded between 2013 and 2016 at three continuous monitoring stations in the urban area of Calama (located in the hyper-arid desert from the Atacama) is presented. The results indicated that the recorded concentrations of PM10, PM2.5, and SO2 exceeded...

According to the current understanding, the adverse health effects of particulate matter (PM) are produced by oxidative stress processes. Hence, the oxidative potential (OP) can be used as an exposure metric for more accurate approaches of the health response to ambient PM. This work explores the relationship between respiratory deposition of size-...

The mass concentration of atmospheric particulate matter (PM) has been systematically used in epidemiological studies as an indicator of exposure to air pollutants, connecting PM concentrations with a wide variety of human health effects. However, these effects can be hardly explained by using one single parameter, especially because PM is formed b...

The mass concentration of atmospheric particulate matter (PM) has been systematically used in epidemiological studies as an indicator of exposure to air pollutants, connecting PM concentrations with a wide variety of human health effects. However, these effects can be hardly explained by using one single parameter, especially because PM is formed b...

Oxidative stress is considered as one of the main mechanisms by which airborne particles produce adverse health effects. Several methods to estimate the oxidative potential (OP) of particulate matter (PM) have been proposed. Among them, the dithiothreitol (DTT) assay has gained popularity due to its simplicity and overall low implementation cost. U...

Air pollution problems can be large, complex, and ill-structured. They can vary from location to location and combine many complex components: urban expansion, increasing vehicles and industrial emissions, biomass burning, geographic and meteorological conditions, cultural aspects, and economic effects. However, the existing research, accumulated k...

Black carbon (BC) or soot is a term used to describe the refractory carbonaceous residues resulting from the incomplete combustion of biomass and fossil fuels. It is one of the most important anthropogenic components of fine particles. BC is relatively resistant to degradation and it can be used as an indicator of biomass burning and anthropogenic...

Air quality regulations in Chile began in 1998 and have historically been based on the average daily concentration of atmospheric particulate matter (PM). Despite these efforts, several Chilean cities, including the Santiago Metropolitan Region, still have air quality issues. This study aims to explore the concept of “Air quality management” in Chi...

This study investigates A severe air quality degradation event occurred in the Santiago Metropolitan Area (SMA), Chile, in June 2014. Meteorological and air quality measurementsfrom 11 stations in the area as well as numerical simulations using the Weather and Research Forecasting (WRF) model were used to explain the main reasons for the occurrence...

In Chile, almost 90% of the population lives in polluted urban areas, such as Santiago Metropolitan Area (SMA, 33.5 S, 70.5 W), the capital of Chile. In SMA, the levels of PM often exceed national air quality standards and guidelines of the World Health Organization. The exceedance of limit values for both PM10 and PM2.5 occurs mainly due to urban...

This studywas designed to evaluate the atmospheric total suspended particle (TSP) and particulate matter (PM10) concentrations and temporal variability in one of the world’s largest open-pit coal mines (El Cerrejon) located in northeast Colombia, during 2012– 2016. The results showed overall average TSP and PM10 concentrations of 86 μgm−3 (CI95% 84...

This study analyzes tropospheric column ozone variability in the southern hemisphere as a function of ozone transport from the stratosphere to the troposphere and photochemical formation. Geographically, the study area was located in the mid-latitudes in South America (33º S), to the west of the Andes mountain range, in an area highly susceptible t...

South America is one of the most vulnerable areas to stratospheric ozone depletion; consequently, an increased amount of UV radiation reaches the Earth’s sur- face in this region. In this study, we analyzed the long-term trend in the total ozone column (TOC) over the southern part of the South American continent from 1980 to 2009. The database used...

The temporal and spatial trends in the variability of PM10 and PM2.5 during the period from 2010 to 2015 in the metropolitan area of Lima-Callao, Peru are studied and interpreted in this work. The mean annual concentrations of PM10 and PM2.5 have ranges (averages) of 133-45 μg m-3 (84 μg m-3) and 35-16 μg m-3 (26 μg m-3) for the monitoring sites un...

Landfill fires are relatively frequent incidents that can result in severe environmental impacts. On the morning of January 15, 2016, a fire occurred at the Santa Marta Lf in the metropolitan area of Santiago (SMA), Chile. The fire triggered public alarm. In the present work, the impact of the Landfill fire on the air quality of the SMA and the pos...

This study analyzed air quality in terms of the concentrations of sub-10 µm and sub-2.5 µm particulate matter (PM10 and PM2.5, respectively) recorded at 23 automated public monitoring stations located in 16 cities in south-central Chile (Rancagua, Rengo, San Fernando, Curicó, Talca, Maule, Chillán and Chillán Viejo, Gran Concepción, Coronel, Los Án...

In this study, we analysed PM10 and PM2.5 concentrations recorded at 23 automated public monitoring stations administered by the Ministry of Environment of the Government of Chile (MMA) and located in 15 cities south of Santiago de Chile.

The relationships between ozone (O3) and its precursors, nitrogen oxides (NOx) and volatile organic compounds (VOCs), were investigated in the VIR region (34° 10′ S, 71° 36′ W), referred to as Libertador General Bernardo O’Higgins of Chile. Observations were obtained from a field study performed at four monitoring sites, which represented different...

Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over 2009–2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresp...

A critical analysis of Chile's National Air Quality Information System (NAQIS) is presented, focusing on particulate matter (PM) measurement. This paper examines the complexity, availability and reliability of monitoring station information, the implementation of control systems, the quality assurance protocols of the monitoring station data and th...

The relationships between ozone (O3) and its main precursors (nitrogen oxides (NOx) and volatile organic compounds (VOCs)) were investigated to establish the ozone production capacities of each VOC. In addition, the O3-NOx-VOC sensibility was investigated. Region VI (Libertador General Bernardo O'Higgins) was studied in this investigation to unders...

In preparation, SAP

In preparation, SAP

A six years (2002-2007) of fine PM2.5 and organic and elemental carbon were analized in a Big city, Santiago of Chile. The contribution of carbonaceous aerosols to primary and secondary fraction was estimated in warm and cool seasons. The results show that there are significant differences between levels in the cold and warm months. The seasonal tr...

Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002-2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to...

The Valparaiso Region is characterized by the presence of air sheds that modulate the general atmospheric circulation with local winds. The ozone concentration in the region increases from the west coast toward the mountainous area, where the concentrations of ozone precursors are lower. In this study, surface ozone (O3), nitric oxide, nitrogen dio...

Dataset Photochemical ozone pollution in the Valparaiso Region, Chile

To improve the current understanding of the ammonia distribution in the major urban area of Chile, measurements of atmospheric NH3 were collected in Santiago during three sampling periods (25 April to 27 May, 11 to 26 June and 27 June to 31 July 2008). Additionally, air quality and meteorological data as well as NH4+, NO3-, SO4= and Ca+2 13 concent...

Cerebrovascular accidents, or strokes, are the second leading cause of mortality and the leading cause of morbidity in both Chile and the rest of the world. However, the relationship between particulate matter pollution and strokes is not well characterized. The association between fine particle concentration and stroke admissions was studied. Data...

Observations were performed in 12 communities of central Chile in order to determine the horizontal gradients of ozone in the Santiago Basin and surrounding valleys. Higher ozone mixing ratios were found northeast of the Santiago Basin and included east of the Aconcagua Valley (~70 km from Santiago) suggesting that photochemical pollution produced...

Particulate matter, the main pollutant in the atmospheric environment of the Santiago city in winter, was analyzed by means of the major water-soluble ionic species obtained under critical episodes of pollution in 2003. The particulate matter samples were collected using the Micro-Orifice uniform deposit impactors, with eight impactor stages connec...

The present study compared 2 methodologies to measure the mercury concentration in soil and their compliance with international standards: cold vapour atomic absorption spectrometry (CVAAS) and thermal decomposition, amalgamation, and atomic absorption spectrophotometry (TDAAS). The limit of detection (LOD), limit of quantification (LOQ), and uncer...

The present work presents a measurement uncertainty evaluation according to Guide to the Expression of Uncertainty in Measurement (GUM) of the concentration of the cations K+ and Li+ and anions NO 3−2 and SO 4−2 in fine airborne particulate matter, refers to particles less than 2.5 μm in diameter (PM2.5), as measured by ion chromatography (US-EPA 3...

A comparison of the ozone primary reference standard photometer serial number 45 (SRP45) against the National Institute of Standards and Technology (NIST) instruments, serial number 0 (SRP0) and 2 (SRP2), has been performed in order to establish the traceability and comparability of ozone measurements made by the Chilean atmospheric science communi...

En el año 2009, la CONAMA publicó la Fase I del Catastro de Sitios con Presencia de Dioxinas y Furanos, Asociados al Uso de Pentaclorofenol en Aserraderos, que permitió contar con una priorización de sitios sospechosos de estar contaminados en las regiones madereras de Chile (VII a X Región). La metodología empleada consideró la identificación y po...

High concentration of fine airborne particulates is considered one of the major environmental pollutants in Santiago, the Chilean Capital city, which in 1997 was declared a PM10 saturated zone. To date there is no control of the amounts of fine and coarse aerosols concentrations and the source and chemical characterizations of the PM2.5 particulate...

El efecto de la contaminación atmosférica en la salud es un asunto de importancia para las políticas públicas en salud y medio ambiente. Se ha demostrado que el material particulado fino MP aumenta el riesgo de mortalidad en la ciudad de Santiago [1]; sin embargo existen evidencias que las partículas ultrafinas ocasionan un daño posiblemente más se...

Santiago de Chile is a big city with huge air quality problems, being one of the most polluted cities in the world. This is aggravated during winter by the topography and meteorological conditions of the city. Although public policies have been developed to minimise the atmospheric aerosol pollution, there is a lack of adequate knowledge and poor c...

El presente libro –“Materiales de referencia y comparaciones interlaboratorios. Herramientas para el control de la calidad en laboratorios de ensayo”- es uno de los productos del proyecto, de tres años, desarrollado por el Laboratorio de Química y Referencia Medio Ambiental (LQRMA) del Centro Nacional del Medio Ambiente (CENMA) de la Universidad de...

El material particulado atmosférico se define como las partículas sólidas y/o liquidas (exceptuando el agua pura) que se encuentra en suspensión en la atmósfera. El concepto de material particulado engloba tanto las partículas sedimentables como las partículas en suspensión. Las partículas atmosféricas pueden ser emitidas por fuentes naturales y an...

La ciudad de Santiago de Chile (33.5º S, 70.6º W), el mayor centro urbano del país, con una población que sobrepasa los seis millones de habitantes, de acuerdo al ultimo censo realizado en el año 2002, está ubicada en el principal valle de la zona central a unos 500 m por sobre el nivel del mar, y está conformada por una superficie de aproximadamen...

El material particulado atmosférico se define como las partículas sólidas y/o liquidas (exceptuando el agua pura) que se encuentra en suspensión en la atmósfera. El concepto de material particulado engloba tanto las partículas sedimentables como las partículas en suspensión. Las partículas atmosféricas pueden ser emitidas por fuentes naturales y an...

This paper describes a tale of three cities - Santiago, Osaka, and Shanghai, and their interrelatedness through the impact of globalization on the three environmental spheres - air, water and soil. Due to the complexity of atmospheric, hydrospheric and pedospheric chemistry, it is necessary to consider and conduct research under the “one atmosphere...

The environmental spheres (atmosphere, hydrosphere, geosphere) are intimately linked through an array of complex interactions through mass and energy transport. Anthropogenic perturbations such as air pollution from combustion, water pollution from raw sewage, and deforestation and land changing resulting in loss of biodiversity can all profoundly...

By means of C-13-NMR spectroscopy and ab initio molecular orbital theory calculations we have analyzed the bridge effect of the C=N bond and the long distance electronic effect of the electron-donor substituents (D: -NO2, -Cl, -H, -CH3, -OCH3, and -N(CH3)(2)) on N-(4-D-benzylidene)-4-nitroanilines (DCNA) and N-(4-nitrobenzylidene)-4-D-ani-line (DNC...

http://cabierta.uchile.cl/revista/20/articulos/pdf/paper6.pdf The determination and characterization of the physical chemical properties of the structures denominated “molecular wires”, belongs to a new and emergent research area known as “molecular electronics”. In this sense, we have studied molecular organic species that have showed intramolecu...

By means of C-13-NMR spectroscopy and AM1 molecular orbital calculations of mono, bi- and tri-methoxy-beta-nitrostyrenes at the meta and para positions, we have characterized a long distance electronic charge transfer pattern on the ethylenic bridge (CH=CH) and on the aromatic ring (Ph) carbon centers, determined by the electron-donor nature of the...

By means of C-13-NMR spectroscopy and ab initio molecular orbital theory calculations, we have analyzed the bridge effect of the C=C, C=N and N=N bonds on the long distance charge transfer of 4-dimethylamino-4'-nitrostilbenoid compounds in the ground electronic state. After a complete spectral assignment of the C-13-NMR signals in these molecular c...

By means of C-13-NMR spectroscopy and AM1 molecular orbital calculations of para-beta-nitrostyrenes, we have found a characteristic long distance charge transfer pattern, where the olefinic bridge (CH=CH) and the aromatic ring (Ph) carbon centres are perturbed according to the donor-nature of the para-substituent groups. After a complete spectral a...

A systematic study of the rotational activation free energy around the Caromatic-Cethylenic bond of para-substituted styrene systems is carried out in the present work from a quantum chemistry point of view.Calculations of the rotational potential barriers in the AM1 approach are developed as function of the electron-donor groups localized on the a...

Para-benzylideneacetones present a characteristic long distance charge transfer pattern, where the olefinic bridge (CH=CH) and the aromatic ring (Ph) carbon centers are perturbed according to the nature of the para-substituent groups. By means of C-13-NMR spectroscopy and AM1 molecular orbital calculations we have found that in this molecular serie...

Internal rotational barriers of aromatic carbonyl compounds were calculated by means of semi-empirical quantum chemical methods such as AM1 and PM3. Rotational potential barriers in the AM1 approach (V-AM1) follow the experimental rotational free energy of activation (Delta G double dagger) according to the linear relationship Delta G double dagger...